With the ESC key-issue out of the way, a new one arises:
As you can see from the attached photos, BGB can be used on two fullscreen modes.
Fullscreen and Fullscreen Stretched.
I would highly prefer the Fullscreen Stretched option as default, however, it is to the extend of my knowledge, not compatible with mGalaxy.
I believe mGalaxy has only been tested with the regular fullscreen option which has masive black boarders around it.
Any help on this is greatly appreciated!